Gauge



. J. J. DUNN 2,400,293

May 14, 1946.

Fild Sept. 22, 1945 M2M wm www,

:HEM:

Patented May 14, 1946 j I; Jerry Jay DumflyEllwood City, Pa., assignor to Na'- I Y .tnnaLTubeCompany a.conversationy of New;

jersey f Application September 22, i943;4 Serial Not50'3g439- comme. (c1;3s'172, v

irwenticm relates toanimprovement in gauges and more particularly to gaugesy for de'- termining the maximum; diameter of aV circle that can Ybe inscribedV Within the threaded section of a tube,l the circle having its center in the axis of the threaded section. TheY Wall/thickness" underY the thread on atube-varies considerably from the Ibasic tl'licltness` towhich the tube is produced. The variationarses from severalcauses among which are the eccentricity ot the-bore,l the variation in Weight', the' metal addedl at wel'ds,v etc'. It is often. import-entete knowthemaximum diameter off anv article that can1 passiatube joint, espe'- cially in: deep wellcasin'gs. In this service,l drillingV bits-and various other objects mustv pass throughv the joints in the-entire lengthv of casing; i

It is important in the interests of economy that the diameter'v of these objects be as-large as possible without danger. of their hangingup in a y on a threaded tube ;v andA A.

Figure 2 is; a. fragmentary view'showing the means tor fastening the gauge toa tube having-a couplingthreaded.thereto. y

`Referring morev particularly tothe drawing,the reference numeral 2 indicates the-threaded end of a tubewhose variationsininternaLdiameter-'is to be gauged. A centering j1ig4 having threads fon they ange I which engage the threads of the tubeZhas al bore 8s for receiving the carriage I0'. The' axis. of -theborexilr andthe 'carriage I-rIl' coincidesI with the axis; ofthe threaded section of the tube. LA gauge I2 isymounted. onthe' outer. end .ofV the carriageilll'and has an anvil I4 which is actuated by means of a rod I6 slidably mounted in bearings I8 on the carriage I0. The inner end of the carriage I0 has a member 20 fastened thereto. A plunger 22 is mounted for sliding. movement in a bore 24 in the member- 20, the center line of the bore 24 being on a radius of the threaded section of the tube. Mounted Within a chamber 26 in the member 20 is a lever'28 having surface 30 which contacts the inner end of the plunger 22. Another surface 32 of the lever contacts the rod I6. Mounted within a bore 34 in the member 20 is a plunger 36 which is urged against the lever 28 by means of the spring 38,

this-hol`ding the lever in engagement with the plunger 22' and-redfIfG;

The operation of the device is as. follows:

'A jig 4 isvscrewed' on the vthreads of the tube thus-locating the axes ofthe rod I6' andi the carriage I 0f ony lthe axis. of-v the threaded portion of the tube.. After the jighas-been threaded in posi'- tion, the plunger 221 will contact the inner. surface ofthe' tubeand? any movement'of Ythe plunger will be transmitted through. the lever 2B and theerod I16 to thegaugea l2.. The leverz'tliY may bet-designed so* that. the movement along: the radius exactly proportional `to the: movement'along the axisehut,

it' desired, the dimensions,v mayr vary from' exact proportionality without;V detracting from the usefulness of :the measurements:v The dial gauge I2 mayifbe replaced-,b3ta micrometer; screw or other device for measuring the movement of therod I 6; along `the axis of the thread The carriage VHI is rotatableabout itsaxis; and: movable along its axis softhat the plunger v222A may be broughtinto ycontact Lwith any part ofthe; inside Ysurface of' the -tubeand the: distancev of. that partici the surface from. the axis of; the threadedY surface determined by reading the measuring device.,

l In orderto translate thegauge readingsinto diameter or Wall thickness, a standard calibrationl unit consisting of aL threaded cylinder, the threads of which are duplicates of the threads on the gtube whichisto be measuredy and having a concentric bore of known diameterisfused. To calibratethe gauge.. thev jig;v is screwed tightly on thepalibrat-ion unit and the yplu-nger 212 brought Y into contact with the surface of:v the concentric bore and-the readingbf the measuringl device noted. This reading corresponds tothe diameter ofthe bore-and after calibration, the reading re corded. for a. tube to which the gauge is applied,

Will-.be that. for thedifference between the diamf4 eter of the bore-.of` the.` calibration unit and. that of the tube being measured. Hence, the diameter soughtbecomestknown.; By notingv afewreadings of the gauge the minimum diameter is determined and located relatively to a point on the circumfer-V ence on the outside of the tube surface.

Ordinarily, the diameter of the drilling bit or other objects to be passed through the tube are fixed with the conditions of intended use. This diameter being known, the` gauge can be used to determine Whether or not a given length of tube can be placed in service.

In many instances, the tube isl furnished with a couplingattached and the jig 4 cannot be used without removing the coupling from the tube. To eliminate the necessity of removing the coupling,

the modified jig shown in Figure 2 is used. The coupling 40, having female threads 42, is screwed on the tube 2. The jig 44, instead of having female threads 5 on its ange l', is provided with male threads 46 for engaging the threads 42 of the coupling 4B. In all other respects the gauge is identical with the gauge shovvnrin Figure 1.

While two embodiments of the inventionhave been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the? ,Y inner surface of said tube, a lever in said carriage following claims.

I claim:

l. A gauge for determining the maximum di- I ameter of a circle that can be inscribed within the threaded section of a tube having its center in the axis of the threaded section which comprises a centering jig adapted to engage the threads of the threaded section of the tube to maintain its axis in coincidence with the axis of the threaded section, an elongated sleeve in said jig, a carriage mounted in said sleeve for rotation about the axis thereof, agauge on the outer end of said carriage, a radial plunger on the inner end of said carriage adapted to contact the inner surface of said tube, and means for transmitting the radial movement of said plunger to said gauge.

2. A gauge for determining the maximum diameter of a circle that can be inscribed within the threaded section of a tube having its center in the axis of the threaded section which comprises a centering jig adapted to engage the threads of the threaded section of the tube to maintain its axis in coincidence withthe vaxis of the threaded section, an elongated sleeve in said jig, a carriage mounted in said sleeve for rotation about the axis thereof and for sliding movement Y longitudinally thereof, a gage on the outer end of said carriage, a plunger adapted to lContact the inner surface of said tube, a rod in said carriage extending from said gauge to a point adjacent said plunger, and means for transmitting the movement of said plunger to said rod to thereby actuate said gauge. K 1 '3. A gauge for determining the maximum diameter of a circle'that can be inscribed within the threaded section "of ay tube having its center in the axis of the threaded section which comprises a centering jig adapted to engage the threads of the threaded section of the tube to maintain its axis in coincidence with the axis of the threaded section, an elongated sleeve in said jig', a carriage mounted in said sleeve for rotation about the axis thereof and forsliding movement longitudinally thereof, a gauge on the outer end of said carriage, a plunger adapted to contact the inner surface of said tube, a rod extending along the axis of said carriage having one end incontact with said gauge and the other end adapted to be actuated by the movement of said plunger. Y 4. A gauge for determining the maximum diameter of a circle that can be inscribed within the threaded section of a tube having its center in the axis of the threaded section which comprises a centering jig adapted to engage the threads of the threaded section of the tube to maintain its axis in coincidence with the axis of the threaded section, an elongated sleeve in said jig, a carriage'mounted in-said sleeve for rotation about the axis thereof `and for sliding movement longitudinally thereof, a gauge on the outer end of said carriage, a plunger adapted to contact the bearing against the inner end of said plunger, a rod extending along the axis of said carriage having one'end incontact with said gauge and the other end in contact with said lever whereby movement of said plunger is transmitted to said gauge.

5. A gauge for determining the maximum diameter of a circle that can be inscribed within the threaded section of a tube having its center in the axis of the threaded section which comprises a centering jig adapted to engage the threads of the threaded section of the tube to maintain its axis in coincidence with the axis of the threaded section, an elongated sleeve in said jig, a carriage mounted in said sleeve for rotation about the axis thereof and for sliding movement longitudinally thereof, a gauge on the outer end of said carriage, a radial plunger adapted to contact the innerv surface of said tube, a lever in said carriage bearing against the inner end of said plungena rod extending along the axis of said carriage having one end in contact with said gauge and the other end in contact with said lever, and means for urging said lever into contact with said radial plunger and said rod whereby movement of said radial plunger is transmitted to said gauge.

6. A gauge for determining the maximum diameter of a circle that caribe inscribedwithin the threaded section of a tubevhaving its center in the axis of the threaded section which'comprises a centering,V jig adapted to engage the threadsof the threaded.. section of the tube to maintain its axis in coincidence with the axis of the threaded section, an elongated sleeve in said jig, a carriage mounted in said sleeve for rotation about the axis thereof and for sliding movement longitudinally thereof, a gaugeon the outer end of said carriage, a radial plunger adapted to contact the inner surface of said tube, a lever in said carriagebearing against the inner end of said plunger, a rod extending along .-the axis of said carriagefhaving one end in contact with said gauge and the other end in contactwith said lever, and, va spring pressed plunger urging said lever into contact with saidV radial plunger and said rod whereby movement of said radial plunger istransmitted to said gauge.

. l- JERRY JAY DUNN. 

